Sheave-block.



B. B. BOSWORTH.

SHEAVE BLOCK.

APPLICATION FILED JUNE 14, 1916.

1,243,585. Patented 001. 16,1917.

Witnesses Enron,

IBIRNEY BOARIDMAN BOSWORTH, OF NEW YORK, 1V. Y.

SHElVE-BLOCK.

Specification of Letters Patent.

Patented Oct. 16, 1917.

Application filed June 14, 1916. Serial No. 103,678.

To all whom it may concern:

Be it known that I, BIRNEY BOARDMAN Boswon'rrr, a citizen of the United States, and a resident of the city of New York, borough of Manhattan, in the county and State of New York, have invented a new and improved sheave-Block, of which the following is a full, clear, and exact description.

This invention relates to small sheave blocks such as are used in pulleys for awnings, elevating racks, boat tackle, etc.

The object of this invention is to produce a sheave block combining the economy, lightness, strength and durability of pressed or bent metal construction with certain mechanical improvements, hereinafter to be described, which enable this sheave block to successfully meet a number of novel and useful operating conditions.

For fuller explication of my invention, reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures,

Figure 1 shows the flat outline of the sheet metal blank from which the sheave casing is formed.

Fig. 2 is a side elevation showing the sheave block and its sheave in appropriate relations and under typical working conditions; and also showing one of the flaps raised clear of the pulley throat to give the rope an increased angle. of operation.

Fig. 3 is an end elevation of the sheave block with its sheave.

The sheave block consists of two parts, a casing A and an attaching ring B. It is designed to carry, by means of an axle, a sheave having a grooved rim and a side concaved between the axle and the rim.

The easing,formed from a single sheet metal blank, consists of the two side members C and the back D.

Each of the two side members O has its two lateral edges extended, in a general plane substantially parallel with that of the side of the sheave, to form wings E, and

the back D is similarly extended by means of flaps F; one main object attained by the several and joint use of said wings and flaps being to follow the rope around the rim of the sheave to such a distance as to guide and retain the rope in the goove of the sheave.

Each of the two side members C is also stamped with a semicircular corrugation H,

concave on the outside and convex on the inside of the said member, following close about the perimeter of the sheave, as indicated in Fig. 2, to further guard the rope so as to prevent its lodgment between the side of the sheave and the inside of the said side memberof the casing.

It is plain that, but for the flaps F, the slackened rope could rise out of the groove and loop over the edges of the wings, in the spaces between the shoulders G and the edges of the back D, and that the flaps F serve to prevent such lodgment. V

Equally, it is plain that, but for the wings E, the slackened rope could similarly rise out'of its groove and loop about the periphery of the sheave side, at the two points where said periphery crosses over the edges of the casing side member, and that the extended wings serve to prevent such lodgment.

The wings E are further provided with shoulders G, having flat bearings with curved approaches at each end of the bearmg.

One object attained by means of the shoulders G is to secure to the sheave block support upon a plane surface, in a relation of lateral stability and in a position perpendicular thereto; and it will be observed that the shoulders G, being disposed on either edge of the sheave block and on pairs of equally extended wings, they do fulfil this object.

A further object attained by means of the shoulders G, in combination with forked, sheave-supporting members, i. 6. members having ends joined together at but one edge of the sheave, and in further combination with the attaching ring B, is to enable the block to be disposed edgewise on a plane surface and put under strain of the rope without bringing the sheave rim into friction contact with the plane surface and without obstructing the rope at the unattached end of the block.

Fig. 2 illustrates an application, in practice, of this three-fold combination, in an instance where one end of the rope descends through an opening in a surface, upon which the wings, where they come in conoac the plane surface, and to protect snrrace pulley throat and the pulle block is attached and supported in the manner described, while the hauling end oi. the rope is free to swing, unobstructed, about the uninclosed sheave at the unattached end of the pulley.

The shoulders G have flat hearings to distribute the strain on the thin material of t t with from undue wear, and each bearing nas curved approaches for easing an ObjQCt around it longitudinally. 7

By referring to Fig. 3, it will be seen tna the flaps F are depressed into the nulley throat so that the inside surfaces wings E are in contact with and bear against the lateral edges of the flaps. Thus the flaps serve to brace the wings and stiffen the sheave block.

it is further plain that the flaps F may be more or less depressed into the pulley throat. The consequen ly form a variable means of eith r enlarging or restricting the p ,lley throat aperture, at will; thus permitting the passing of knot or loop thr 1 preventing the accicemal withdrawal of same.

It is also plain that the tiaps F may be raised ei'rtirely out of he pulley throat to give the sheave rope an increased angle of operation, as in Fig. 2.

The laps F have the edges of their free ends concaved for additional. clearance in threading the sheave rope through the pulle; throat.

further reference to Fig. it will be t ns or members C, at the open bent inwardly to lie in a concavity in side of the sheave; JhUS serving to guide the open end oi the block over an object lying, or moving, along the side of the sheave.

I claim 1. As an article of manufacture, a sheave block casing formed of a single piece of sheet metal shaped to provide two side members and a back from which depend the side members in parallel relation one to the other, each side member 'having integral wings at the sides and the said back being provided with integral flaps "forming with the said wings the throat oil the sheave block, the said back flaps bein adapted to bent to extend between opposite wings to form a brace for the wings and a restricted throat, and the said back flaps or either of them being adapted to be bent upwardly to form an enlarged throat.

2. As an article of manufacture, a sheave block. casing formed of a single piece of sheet metal bent to provide two parallel side members and a back from which depend the said side members, the latte having integral wings at the sides, portionsiof the edges of the wings being straight t form fiat bearings, the said back ha *ing integral flaps e5:- tending between the said wings of the side members and terminating an] cent the said flat bcarhigs.

3. As an article or" manufacture, a sheave bloclccasing formed of a single piece of sheet metal bent to provide two parallel side members and a back from which depend the said side members, the latter having integral wings at the sides, portions of the edges of the wings being straight to form flat bearings and the edge portions adjacent the ends ot the fiat bearings being curved, the said back ha ing integral curved flaps extending between the said wings at the curt-ed portions extending from the flat hearings to the said baclr.

a is an article oi manufacture, a sheave block casing -formed of a. single piece of sheet metal bent to provide two parallel side members and a back from which depend the said side members, the lat er having integral wings at the sides, edges of the wings being straight to form flat bearings, the edge portions or" the wings between one one of the flat hearings and the back being concave and the ed 'e poi ns 01 the wings adja ent the other end of the flat bearings being convex, the said back having integral concave flaps itting between the said wings of the side members at t le said concave edge portions thereof.

In testimony whereof I have signed my name to this speciacation in the presence of two subscribing witnesses.

BIRNEY BOARDMAN BOSWORTH.

Witnesses:

Msnennnrrn C. Vennnr, Mann J. QUIMBY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.

portions of the 

